On Thu, 2014-04-03 at 09:52 +0200, Ortwin Glück wrote: > On 02.04.2014 18:42, Eric Dumazet wrote: > > You could post a tcpdump maybe ? > > This is a dump from on the tun interface (traffic inside the tunnel). > It's an scp upload of a 2MB file. I aborted after a while when not much > progress was seen anymore, but you get the idea. > > What I see: > - Frame 28: long delay because I had to enter the key password > - Frame 31: the packets seems to be out of order. It has a sequence > number that is far ahead of previously sent sequence no's. Some > duplicates and retransmissions follow. That pattern repeats randomly all > over the trace. > - from Frame 73 on: ping pong of ACKs and data, while the data is > delayed by ~200ms caused by the select(). The ping pong also shows that > there are virtually no packets in flight (see also Window size).
It seems TSO support is broken. Your trace have no 'big' packets but holes like : 00:41:35.832695 IP 10.243.88.168.35846 > 10.185.85.69.22: Flags [.], ack 6093, win 310, options [nop,nop,TS val 78054 ecr 3191538976], length 0 00:41:35.855990 IP 10.243.88.168.35846 > 10.185.85.69.22: Flags [P.], seq 6696:6776, ack 6093, win 310, options [nop,nop,TS val 78060 ecr 3191538976], length 80 00:41:36.047465 IP 10.185.85.69.22 > 10.243.88.168.35846: Flags [P.], seq 6093:6141, ack 6776, win 218, options [nop,nop,TS val 3191539191 ecr 78060], length 48 missing 6776:14144 sequence (6 segments) 00:41:36.048766 IP 10.243.88.168.35846 > 10.185.85.69.22: Flags [.], seq 14144:15372, ack 6141, win 310, options [nop,nop,TS val 78108 ecr 3191539191], length 1228 00:41:36.057995 IP 10.185.85.69.22 > 10.243.88.168.35846: Flags [.], ack 6776, win 218, options [nop,nop,TS val 3191539202 ecr 78060,nop,nop,sack 1 {14144:15372}], length 0 You are 'saved' because retransmits do not use TSO : 00:41:36.058050 IP 10.243.88.168.35846 > 10.185.85.69.22: Flags [.], seq 6776:8004, ack 6141, win 310, options [nop,nop,TS val 78110 ecr 3191539202], length 1228 00:41:36.058070 IP 10.243.88.168.35846 > 10.185.85.69.22: Flags [.], seq 8004:9232, ack 6141, win 310, options [nop,nop,TS val 78110 ecr 3191539202], length 1228 Also receiver seems to be unable to open TCP window, but thats a secondary problem. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/